U.S. patent number 10,585,295 [Application Number 16/034,946] was granted by the patent office on 2020-03-10 for display device, electronic apparatus and display method.
This patent grant is currently assigned to TIANMA MICROELECTRONICS CO., LTD.. The grantee listed for this patent is Tianma Japan, Ltd.. Invention is credited to Yukie Keicho, Jin Matsushima, Tetsushi Sato, Koji Shigemura.
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United States Patent |
10,585,295 |
Matsushima , et al. |
March 10, 2020 |
Display device, electronic apparatus and display method
Abstract
A display device includes a display panel including a plurality
of pixels arrayed along first and second directions, a distribution
unit that distributes light emitted from each pixel configured to
display a parallax image corresponding to each of a plurality of
viewpoints, and a light blocking unit between the display panel and
the distribution unit. The distribution unit distributes light
emitted from each of the pixels to the plurality of viewpoints
along the first direction in a first display state where the
display panel displays a parallax image, or stops distributing
emitted light in a second display state, displaying a planar image.
The light blocking unit forms, along the first direction, a
plurality of first light blocking areas each extending along the
second direction blocking some emitted light in the first display
state, and stops forming the first light blocking areas in the
second display state.
Inventors: |
Matsushima; Jin (Kanagawa,
JP), Shigemura; Koji (Kanagawa, JP),
Keicho; Yukie (Kanagawa, JP), Sato; Tetsushi
(Kanagawa, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Tianma Japan, Ltd. |
Kanagawa |
N/A |
JP |
|
|
Assignee: |
TIANMA MICROELECTRONICS CO.,
LTD. (Shenzhen, CN)
|
Family
ID: |
64998835 |
Appl.
No.: |
16/034,946 |
Filed: |
July 13, 2018 |
Prior Publication Data
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|
|
Document
Identifier |
Publication Date |
|
US 20190018256 A1 |
Jan 17, 2019 |
|
Foreign Application Priority Data
|
|
|
|
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Jul 13, 2017 [JP] |
|
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2017-137228 |
Apr 13, 2018 [JP] |
|
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2018-77983 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B
30/27 (20200101); G02B 3/14 (20130101); G02B
27/60 (20130101); G02B 30/25 (20200101); G09G
2320/0242 (20130101) |
Current International
Class: |
G02B
27/60 (20060101); G02B 3/14 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
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|
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2013-55695 |
|
Mar 2013 |
|
JP |
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2014-41355 |
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Mar 2014 |
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JP |
|
Primary Examiner: Li; Tracy Y.
Attorney, Agent or Firm: Young & Thompson
Claims
What is claimed is:
1. A display device, comprising: a display panel including a
plurality of pixels that are arrayed along a first direction and a
second direction and that are configured to display a parallax
image or a planar image; a distribution unit that distributes light
emitted from each pixel that is configured to display a parallax
image corresponding to each of a plurality of viewpoints; and a
light blocking unit that is disposed between the display panel and
the distribution unit and that blocks part of the emitted light,
wherein the distribution unit distributes light emitted from each
of the pixels to each of the plurality of viewpoints along the
first direction in a first display state where the display panel
displays a parallax image, or stops distributing emitted light in a
second display state where the display panel displays a planar
image, and in the first display state, the light blocking unit
forms a plurality of first light blocking areas arranged along the
first direction, one of the first light blocking areas that blocks
part of the emitted light extending along the second direction, and
in the second display state, the light blocking unit stops forming
the first light blocking areas.
2. The display device according to claim 1, wherein the
distribution unit forms, along the first direction, a plurality of
first separation areas each extending along the second direction in
the first display state, and the light blocking unit forms each of
the first light blocking areas at each boundary between the first
separation areas in the first display state.
3. The display device according to claim 2, wherein the
distribution unit is a liquid crystal lens forming a
lenticular-lens-like refractive index profile extending in the
second direction, the liquid crystal lens being formed at each of
the first separation areas, and the boundary is a boundary between
adjacent two of the liquid crystal lenses.
4. The display device according to claim 2, wherein the
distribution unit changes a width in the first direction of each of
the first separation areas depending on the number of viewpoints in
the first display state, and the light blocking unit forms each of
the first light blocking areas at each boundary between the first
separation areas in correspondence to the width of the first
separation area after change.
5. The display device according to claim 1, wherein the
distribution unit switches between a first distribution state where
light emitted from each of the pixels is distributed to each of the
plurality of viewpoints along the first direction and a second
distribution state where light emitted from each of the pixels is
distributed to each of the plurality of viewpoints along the second
direction, and the light blocking unit forms, along the first
direction, a plurality of first light blocking areas extending
along the second direction that block part of the emitted light in
the first distribution state and the first display state, and
forms, along the second direction, a plurality of second light
blocking areas extending along the first direction that block part
of the emitted light in the second distribution state and the first
display state.
6. The display device according to claim 5, wherein the
distribution unit forms, along the first direction, the plurality
of first separation areas extending along the second direction in
the first distribution state, and forms, along the second
direction, a plurality of second separation areas extending along
the first direction in the second distribution state, and the light
blocking unit forms each of the first light blocking areas at each
boundary between the first separation areas in the first
distribution state, and forms each of the second light blocking
areas at each boundary between the second separation areas in the
second distribution state.
7. The display device according to claim 5, further comprising a
posture detection unit that detects a posture of an apparatus
including the display device, wherein the distribution unit
switches between the first distribution state and the second
distribution state depending on the posture detected by the posture
detection unit.
8. The display device according to claim 1, wherein each of the
pixels includes a plurality of sub pixels that are separated by a
plurality of primary colors and arrayed along the first direction
and the second direction, and the plurality of sub pixels aligned
along the first direction or the second direction are equal in
number for each of the different colors within each of the
pixels.
9. The display device according to claim 8, wherein the sub pixels
adjacent to each other along the first direction and the second
direction have different colors from each other.
10. The display device according to claim 1, wherein the light
blocking unit is a liquid crystal barrier comprising two sheets of
transparent substrates that face each other, a liquid crystal layer
sealed between facing surfaces of the transparent substrates and an
electrode arranged on at least one of the facing surfaces, the
liquid crystal barrier aligning liquid crystal molecules in the
liquid crystal layer based on voltage applied from an external
source to the electrode and forming the first light blocking areas
extending along the second direction.
11. The display device according to claim 1, wherein the first
direction and the second direction are perpendicular to each
other.
12. The display device according to claim 1, further comprising a
position detection unit that detects a position of an observer,
wherein the distribution unit stops distributing the emitted light,
and the light blocking unit changes a forming width and a forming
position of the first light blocking areas along the first
direction depending on the position of the observer detected by the
position detection unit after stopping distribution of the emitted
light in the first display state.
13. An electronic apparatus equipped with the display device
according to claim 1.
14. The display device according to claim 1, wherein the first
direction is a horizontal direction of the light blocking unit, and
the second direction is a vertical direction of the light blocking
unit.
15. A display method for causing a display device to execute
processing, the display device including a display panel including
a plurality of pixels that are arrayed along a first direction and
a second direction and that are configured to display a parallax
image or a planar image, a distribution unit that distributes light
emitted from each pixel configured to display a parallax image
corresponding to each of a plurality of viewpoints, and a light
blocking unit that is disposed between the display panel and the
distribution unit and that blocks part of the emitted light, the
display device executing processing of: distributing light emitted
from each of the pixels to the plurality of viewpoints along the
first direction in a first display state where the display panel
displays a parallax image, or stopping distribution of emitted
light in a second display state where the display panel displays a
planar image, by the distribution unit; in the first display state,
forming, by the light blocking unit, a plurality of first light
blocking areas arranged along the first direction and extending
along the second direction to block part of the emitted light; and
in the second display state, stopping formation of the first light
blocking areas.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
This non-provisional application claims priority under 35
U.S.C..sctn. 119(a) on Japanese Patent Application No. 2017-137228
filed in Japan on Jul. 13, 2017 and Japanese Patent Application No.
2018-77983 filed in Japan on Apr. 13, 2018, the entire contents of
which are hereby incorporated by reference.
FIELD
The present disclosure relates to a display device, an electronic
apparatus and a display method.
BACKGROUND
A display device displaying a three-dimensional stereoscopic image
without using glasses for three-dimensional stereoscopic display
has been proposed (for example, Japanese Patent Application
Laid-Open No. 2013-55695 and Japanese Patent Application Laid-Open
No. 2014-41355). Furthermore, a display device with a function of
displaying a three-dimensional stereoscopic image or a
two-dimensional image (hereinafter, appropriately referred to as a
3D display device) has been proposed.
The three-dimensional stereoscopic image display is called "3D
(dimension) display" while the two-dimensional image display is
called "2D display."
For a 3D display device, degradation in image quality may occur due
to unevenness of display color, so-called color moire, at the time
of 2D display.
SUMMARY
One aspect of the display device according to the disclosure
comprises a display panel including a plurality of pixels that are
arrayed along a first direction and a second direction and that are
configured to display a parallax image or a planar image; a
distribution unit that distributes light emitted from each pixel
configured to display a parallax image corresponding to each of a
plurality of viewpoints; and a light blocking unit that is disposed
between the display panel and the distribution unit and that blocks
part of the emitted light, and the distribution unit distributes
light emitted from each of the pixels to the plurality of
viewpoints along the first direction in a first display state where
the display panel displays a parallax image, or stops distributing
emitted light in a second display state where the display panel
displays a planar image, and the light blocking unit forms, along
the first direction, a plurality of first light blocking areas each
extending along the second direction that block part of the emitted
light in the case of the first display state, and stops forming the
first light blocking areas in the case of the second display
state.
It is to be understood that both the foregoing general description
and the following detailed description are exemplary and
explanatory and are not restrictive of this disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 simply depicts 3D display.
FIG. 2 simply depicts 3D display.
FIG. 3 is an example of the configuration of a display device
provided with a light blocking member.
FIG. 4 is an example of the configuration of the display device
provided with the light blocking member.
FIG. 5 depicts a problem for a related art.
FIG. 6 depicts a problem for the related art.
FIG. 7 depicts a problem for the related art.
FIG. 8A and FIG. 8B depicts a problem for the related arts.
FIG. 9A and FIG. 9B respectively depict landscape display and
portrait display.
FIG. 10A and FIG. 10B depict a problem for the related art.
FIG. 11A and FIG. 11B are perspective views of an electronic
apparatus with a display device.
FIG. 12 is a block diagram illustrating an example of the
configuration of the display device.
FIG. 13 is a partial cross-sectional view illustrating an example
of the configuration of the display device.
FIG. 14 is a partial cross-sectional view illustrating an example
of the configuration of a light blocking unit.
FIG. 15 depicts an example of the configuration of electrodes.
FIG. 16A and FIG. 16B simply depict 3D display.
FIG. 17A and FIG. 17B simply depict 3D display.
FIG. 18A and FIG. 18B simply depict 2D display.
FIG. 19A and FIG. 19B simply depict 2D display.
FIG. 20A and FIG. 20B are illustrative views of other examples of
array patterns of pixels.
FIG. 21A and FIG. 21B are illustrative views of other examples of
array patterns of pixels.
FIG. 22A and FIG. 22B are illustrative views of examples of array
patterns of sub pixels concerning the three primary colors.
FIG. 23A and FIG. 23B are illustrative views of other examples of
array patterns of sub pixels concerning the three primary
colors.
FIG. 24 is a flowchart depicting an example of a processing
procedure to be executed by a control unit.
FIG. 25 illustrates another example of the configuration of the
display device.
FIG. 26A and FIG. 26B depict image display directed to multi
viewpoints.
FIG. 27A to 27F depict a problem for a related art.
FIG. 28A and FIG. 28B simply depict image display directed to four
viewpoints.
FIG. 29A and FIG. 29B simply depict image display directed to four
viewpoints.
FIG. 30A and FIG. 30B are illustrative views when image display
directed to multi viewpoints is made.
FIG. 31A and FIG. 31B are illustrative views when image display
directed to multi viewpoints is made.
FIG. 32A and FIG. 32B are illustrative views when image display
directed to multi viewpoints is made.
FIG. 33 is a flowchart depicting an example of a processing
procedure to be executed by a control unit.
FIG. 34 is a block diagram illustrating an example of the
configuration of a display device.
FIG. 35A and FIG. 35B depicts the outline of 3D display
processing.
FIG. 36A and FIG. 36B simply depict 3D display.
FIG. 37A and FIG. 37B illustrate a state where the forming
positions of light-blocking areas are switched depending on the
position of the viewpoint of an observer.
FIG. 38A and FIG. 38B depict 4-viewpoint display.
FIG. 39 is a flowchart depicting an example of a processing
procedure to be executed by a control unit.
DETAILED DESCRIPTION
The present invention will be described in detail with reference to
the drawings illustrating embodiments.
First, as a related art being a precondition of the present
embodiments, description is made on a display device 310 that is
mounted on an electronic apparatus 301 and has functions of
performing 3D display or 2D display and of performing landscape
display or portrait display.
Referring now to FIG. 1 and FIG. 2, 3D display will be described.
FIG. 1 and FIG. 2 simply depict 3D display. FIG. 1 and FIG. 2
illustrate the display screen of the display device 310 when it
performs 3D display with a partial area schematically extracted
from the display screen. Note that the schematic diagram of the
electronic apparatus 301 is depicted together at the lower part of
FIG. 1. FIG. 1 illustrates a front view of this area while FIG. 2
illustrates a cross-sectional view when viewed from the inside of
the display surface.
The electronic apparatus 301 is a smartphone, a tablet-type device,
a personal computer, a mobile phone or the like, though not limited
thereto, but any electronic apparatus equipped with the display
device 310. The following description will be made assuming that
the electronic apparatus 301 is a smartphone.
The display device 310 is a display device such as a liquid crystal
display or an organic light emitting diode display (OLED). The
following description will be made assuming that the display device
310 is a liquid crystal display device. The display device 310 has
a rectangular display surface, for example, on which an image is to
be displayed. Note that a side of the display device 310 on which
the display surface is provided is regarded as a front side while
the opposite side thereto is regarded as a back side. Here, a
direction along one side of the display surface is regarded as a
first direction x while the direction along the other side crossing
the first direction x is regarded as a second direction y. More
specifically, as illustrated at the lower part of FIG. 1, a
direction along the long side of the display surface is regarded as
the first direction x while a direction along the short side is
regarded as the second direction y. Furthermore, as illustrated in
FIG. 1, the state where the electronic apparatus 301 is placed with
the second direction y set as a vertical direction is called a
horizontal (i.e., landscape) posture. Unlike FIG. 1, the state
where the electronic apparatus 301 is placed with the first
direction x set as a vertical direction is called a vertical (i.e.,
portrait) posture (see FIG. 9B).
The display device 310 is provided with a display panel 311 having
multiple 3D pixels arrayed along the first direction x and the
second direction y. Here, there are groups of sub pixels for
forming right eye viewpoint images and left eye viewpoint images.
When one group of sub pixels disables white display, it can be
defined as a 3D pixel. In contrast, when one group of sub pixel
enables white display, it can be defined as a pixel. More
specifically, as illustrated in FIG. 1, 3D pixels each including
multiple sub pixels are arrayed along the first direction x and the
second direction y. FIG. 1 depicts sub pixels each concerning one
of the primary colors are arrayed, assuming that the display panel
311 displays the three primary colors of RGB (R: red, G: green, B:
blue). In FIG. 1, for purposes of description, sub pixels along the
first direction x are numbered H1 to H6 while sub pixels along the
second direction y are numbered V1, V2 . . . . In FIG. 1, each 3D
pixel consists of sub pixels of 2.times.1 including two columns (H1
and H2, H3 and H4, or H5 and H6) in the first direction x and one
column (V1 or V2) in the second direction y. That is, FIG. 1
illustrates 3D pixels of 3.times.6. In FIG. 1, on the display panel
311, sub pixels each having R, G or B of the primary colors are
alternately arranged in this order along the first direction x
while all the sub pixels arranged along the second direction y has
a uniform color of any one of R, G and B. In FIG. 1, one 3D pixel
is not able to display an arbitrary color while multiple 3D pixels
together may display an arbitrary color when subjected to image
processing.
In the case of 3D display, the display panel 311 displays a
parallax image for each viewpoint along the first direction x or
the second direction y. In the example depicted in FIG. 1, the
display panel 311 alternately displays a parallax image for right
eye and a parallax image for left eye along the first direction x.
As illustrated in FIG. 1, for example, the display panel 311
alternately displays a right eye image (image displayed by the sub
pixel that is hatched) and a left eye image (image displayed by the
sub pixel that is not hatched) at an array pitch corresponding to
one column of a sub pixel along the first direction x.
The display device 310 includes an optical element that distributes
a parallax image for each viewpoint to be displayed on the display
panel 311 to the viewpoints of the observer. The optical element is
a liquid crystal lens, for example. Note that the optical element
is, without being limited to the liquid crystal lens, only required
to have a function of distributing a parallax image for each
viewpoint to the viewpoints of the observer by electrowetting,
moving of optical components, charging or discharging gas or liquid
to a transparent contracting member or the like. The following
description is made assuming that the optical element is a liquid
crystal lens (not illustrated in FIG. 1 and FIG. 2) that makes a
light beam separation direction dynamically switchable in
accordance with the display orientation of the parallax images on
the display panel 311. The liquid crystal lens is placed in front
of the display panel 311, and a liquid crystal layer is configured
to be sealed between two sheets of electrode substrates that face
each other. The liquid crystal molecules in the liquid crystal
layer are aligned depending on the voltage applied across the
substrates to allow the liquid crystal lens to function as a pseudo
optical lens. In the case where the liquid crystal lens is
switchable between ON and OFF, the display device 310 turns the
liquid crystal lens off at the time of 2D display.
The display device 310 drives the liquid crystal lens to form a
lens-shaped refractive index profile that protrudes toward the
front side, that is, a separation area 3124 indicated by dashed
lines in FIG. 1. As illustrated in FIG. 1, the separation area 3124
is formed to have substantially the same width as the display width
of a pair of the right eye image and the left eye image so as to
extend along the second direction y. By forming multiple separation
areas 3124 along the first direction x, a lenticular-lens-like
refractive index profile in which multiple cylindrical lenses
extending along the second direction y are arranged along the first
direction x is formed as illustrated in FIG. 1 and FIG. 2. As
indicated by arrows in FIG. 2, the separation area 3124 distributes
light emitted from the display panel 311 and incident to the liquid
crystal lens to two viewpoints located along the first direction x.
If the right eye and the left eye of the observer are positioned
along the first direction x, the emitted light beams concerning the
right eye images and the left eye images are incident to the right
eye and the left eye of the observer, respectively. This allows the
observer to stereoscopically perceive a display image.
In the configuration illustrated in FIG. 1 and FIG. 2, however,
display characteristics may degrade at the boundary portions
between the separation areas 3124. That is, as illustrated in FIG.
2, due to alignment disorder of liquid crystal molecules in the
liquid crystal lens, light emitted from the display panel 311 is
prone to scatter at the boundary portions between the separation
areas 3124. Thus, the display characteristics are prone to degrade
at this area.
To solve the problem, a light blocking member such as a black
matrix or the like may be provided at each of the boundary portions
between the separation areas 3124. FIG. 3 and FIG. 4 depict
examples of configurations in the case where the light blocking
members 313 are provided. As indicated by bold lines in FIG. 3, the
light blocking member 313 is an elongated rectangular member, for
example, and placed between the display panel 311 and the liquid
crystal lens. More specifically, multiple light blocking members
313 are provided in stripes along the second direction y so as to
cover the boundaries between the separation areas 3124. Thus, the
light emitted from the display panel 311 and incident to the
boundary areas can be blocked, which solves the above-described
problem.
In the case where the light blocking members 313 are provided as
illustrated in FIG. 3 and FIG. 4, however, the inventors of the
present application found the following problems. FIG. 5 and FIG. 6
depict the problem for related arts.
FIG. 5 illustrates the display screen with the central area and
right and left end areas extracted when the display device 310
performs 3D display. Similarly to FIG. 4 or the like, FIG. 5
depicts at the upper part a cross-sectional view when the central
areas and the right and left end areas of the display screen are
viewed from the inside of the display screen.
In view of the actual design of the display device 310, the
boundary between 3D pixels and the light blocking member 313 are
not aligned with each other. FIG. 3 and FIG. 4 illustrate that the
light blocking member 313 is positioned on the boundary between 3D
pixels. In the actual display device 310, however, the forming
width of the separation area 3124 is designed to be slightly
shorter than the array pitch of each 3D pixel since emitted light
is collected at the optimum visible position for a stereoscopic
image (generally, the position of the viewpoint on the normal
extending from the center of the display panel 311). Hence, the
light blocking member 313 provided at the boundary portion between
the separation areas 3124 is also designed to be slightly shorter
than the array pitch of each 3D pixel. Accordingly, as shown in
FIG. 5, the boundary between 3D pixels is in alignment with the
light blocking member 313 at the center of the display panel 311
while the boundary between 3D pixels is greatly out of alignment
with the light blocking member 313 at the ends of the display panel
311.
Due to the misalignment as described above, color moire may occur
when the display device 310 performs 2D display. FIG. 6
conceptually illustrates a state where the display device 310
performs 2D display without driving the liquid crystal lens. For
the purposes of description, FIG. 6 depicts these display areas
when viewed from the front at the upper part thereof unlike FIG.
5.
As depicted at the upper center in FIG. 5, the display device 310
turns the liquid crystal lens off when performing 2D display so as
not to display the separation area 3124. Furthermore, the display
device 310 uniformly displays a planar image along the first
direction x without alternately displaying a parallax image for
right eye and a parallax image for left eye.
Since the light blocking members 313 are provided, light emitted
from each 3D pixel of the display panel 311 is partially blocked by
the blocking members 313. At the center of the display panel 311,
for example, sub pixels each having R, G or B are partially covered
by the light blocking members 313. This causes degradation in
brightness.
Meanwhile, at the center of the display panel 311, the boundaries
between 3D pixels are in alignment with the light blocking members
313, and thus the 3D pixels are uniformly covered by the light
blocking members 313 for each of the primary colors R, G and B.
Accordingly, color moire does not occur at the center of the
display panel 311.
In contrast, at the ends of the display panel 311, the boundaries
between 3D pixels are greatly out of alignment with the light
blocking members 313. Thus, as illustrated in FIG. 6, sub pixels
that are not covered by the light blocking members 313 periodically
appear. Accordingly, unevenness in the brightness of each of the
primary colors R, G and B occurs, which may cause color moire.
FIG. 7 is an illustrative view illustrating a state where the
direction in which sub pixels of the primary colors are arrayed is
changed. FIG. 7 illustrates a state where the direction in which
sub pixels each having R, G or B of the primary colors are arrayed
is changed from that in FIG. 5. In FIG. 5, sub pixels each having
R, G or B of the primary colors are alternately arranged along the
first direction x while in FIG. 7 while they are alternately
arranged along the second direction y.
In the example in FIG. 7, sub pixels each having R, G or B of the
primary colors are alternately arranged along the second direction
y, and the light blocking members 313 extend along the second
direction y. Accordingly, the 3D pixels are uniformly covered by
the light blocking members 313 for each of the primary colors R, G
and B, which makes color moire less likely to occur.
The light blocking members 313, however, extending in the second
direction y function as a parallax barrier. Thus, a light beam
separation action works along the first direction x, though too
small for the observer to stereoscopically perceive the planar
image. The light beam separation action causes a phenomenon in
which the light blocking members 313 are viewed in an enlarged
manner at a certain degree of visible distance away from the
display panel 311. Such a phenomenon is called "3D moire" below for
the purposes of discrimination from color moire.
By the light beam separation action in the first direction x,
pixels that are hardly visible may occur depending on the visual
angle. Accordingly, the resolution varies depending on the visual
angle.
FIG. 8A and FIG. 8B is an illustrative view in the case where the
extending direction of the separation area 3124 (although not
illustrated) is changed at the time of 3D display. FIG. 8A and FIG.
8B respectively illustrate cases where the extending directions of
the separation areas 3124 are tilted from those in FIG. 5 and FIG.
7. More specifically, the extending direction of the separation
areas 3124 are tilted at a slight angle and shifted from the second
direction y. In accordance with the extending directions of the
separation areas 3124, the light blocking members 313 are also
tilted at a slight angle and shifted from the second direction y
for blocking the light emitted from the display panel 311 and
incident to the boundary portion between the separation areas 3124.
By tilting the light blocking members 313, the sub pixels each
having primary color R, G or B are uniformly covered by the light
blocking members 313 when the display panel 311 is viewed as a
whole and thus, which may prevent color moire from occurring.
In the configuration depicted in FIG. 8A and FIG. 8B, however, a
light beam separation action may work in the direction vertical to
the extending direction of the light blocking member 313 due to the
light blocking members 313. Accordingly, 3D moire described above
may occur. Furthermore, similarly to FIG. 7, due to the work of the
light beam separation action, pixels that are hardly visible may
occur depending on the visual angle, and the resolution may
vary.
The provision of the light blocking members 313 for 3D display may
lead to degradation in brightness as well as color moire and 3D
moire at the time of 2D display.
The following describes a case where switching between the
landscape display and the portrait display as well as the switching
between the 3D display and 2D display are performed, and the
problem arising therefrom. FIG. 9A and FIG. 9B depict landscape
display and portrait display. FIG. 9A depicts a case where the
display device 10 is placed in a horizontal posture to perform the
landscape display. FIG. 9B depicts a case where the display device
10 is placed in a vertical posture to perform the portrait
display.
Unlike FIG. 1 to FIG. 7, FIG. 9A and FIG. 9B depict a case where
the display panel 311 displays four primary colors including R, G,
B plus W (white). In FIG. 9A and FIG. 9B, each pixel consists of
sub pixels of 4.times.4 including four columns in the first
direction x and four columns in the second direction y. That is,
FIG. 9A and FIG. 9B depict pixels of 2.times.2. In FIG. 9A and FIG.
9B, for purposes of description, sub pixels along the first
direction x are numbered H1 to H4 while sub pixels along the second
direction y are numbered V1 to V4.
Note that the adjacent sub pixels along the first direction x and
the second direction y are arranged to have different primary
colors so as to achieve color compensation. By assigning different
primary colors to the adjacent sub pixels along the x direction and
the y direction, display unevenness in each pixel can be
reduced.
The display device 310 switches the form of display to either the
landscape display or the portrait display depending on the
orientation of its own apparatus. More specifically, the display
device 310 displays an image in a horizontal direction or a
vertical direction depending on the placed state, whether it is
placed in the horizontal posture or in the vertical posture. In the
placed state illustrated at the lower part in FIG. 9A, for example,
the display device 310 performs landscape display. In the placed
state illustrated at the lower part in FIG. 9B, the display device
310 performs portrait display.
Description is first made on where 3D display is performed in the
landscape form. In this case, the display device 310 drives the
liquid crystal lens to form separation areas 3124. Here, the
display device 310 switches the liquid crystal lens to a first
distribution state in accordance with the landscape display where
light emitted from each of the pixels of the display panel 311 is
distributed along the first direction x. Thus, the emitted light
concerning each of the parallax images is distributed to two
viewpoints along the first direction x. More specifically,
similarly to FIGS. 1 to 6, on the display device 310, the forming
width of the separation areas 3124 is substantially the same as the
display width of a pair of a right eye image and a left eye image,
and a first separation areas 3124a extending along the second
direction y are formed.
In the case of the portrait display, the display device 310
switches to a second distribution state where light emitted from
each of the pixels is distributed along the second direction y.
More specifically, as illustrated in FIG. 9B, the display device
310 switches the extending direction of the first separation area
3124a formed by the liquid crystal lens to the first direction x to
form, along the second direction y, multiple second separation
areas 3124b corresponding to a lenticular-lens-like refractive
index profile. Thus, emitted light concerning each of the parallax
images is distributed to two viewpoints along the second direction
y.
It is noted that the first separation area 3124a and the second
separation area 3124b are collectively referred to as a separation
area 3124 below for convenience.
Even in the case where switching is made between the landscape
display and the portrait display as illustrated in FIG. 9A and FIG.
9B, light emitted from the display panel 311 may scatter, which is
likely to degrade the display characteristics due to alignment
disorder of liquid crystal molecules at the boundary portions
between the separation areas 3124. Here, the light blocking members
313 described above may be provided at the boundary between the
separation areas 3124.
Since the display device 310 switches the distribution state of the
liquid crystal lens depending on the display state of the display
panel 311, the light blocking member 313 in a matrix is provided
along the first direction x and the second direction y so as to
cover the boundary between the first separation areas 3124a and the
boundary between the second separation areas 3124b. Thus, light
emitted from the display panel 311 and incident to the boundary
portion is blocked in the landscape display as well as in the
portrait display.
However, in the case where the light blocking members 313 are
provided as illustrated in FIG. 9A and FIG. 9B, the inventors of
the present application found the following problems. FIG. 10A and
FIG. 10B depict a problem for the related art. FIG. 10A and FIG.
10B conceptually depict a state where the display device 310
performs 2D display without driving the liquid crystal lens.
An example in the case of displaying in a landscape form
illustrated in FIG. 10A will be described. That is, the display
panel 311 is placed with the second direction y set as a vertical
direction. In the state depicted in FIG. 10A, since the display
device 310 does not drive the liquid crystal lens, light emitted
from each pixel is not essentially separated. As illustrated in
FIG. 7, etc., however, the light blocking members 313 extending
along the second direction y function as a parallax barrier to
cause the light beam separation action to work along the first
direction. The brightness and chromaticity of the collection of sub
pixels of 1.times.4 arrayed in each of the columns H1, H2, H3 and
H4 arranged along the first direction x are perceived by the
integrated value of the sub pixels positioned at V1, V2, V3 and V4.
In the case of considering the collection of the four sub pixels
arranged in the column H1 in the vertical direction in the drawing,
the brightness and chromaticity of the collection of the sub pixels
are perceived by the integrated value of the sub pixels R, B, W and
G respectively positioned at V1, V2 V3 and V4. Here, since the
light blocking member 313 also has a part extending along the first
direction x, the sub pixels of V1 and V4 positioned at the upper
and lower ends in the drawing for each pixel are partly covered.
Accordingly, in the case of white display on the display device
310, for example, the integrated value along the second direction y
concerning the brightness and chromaticity of emitted light in the
pixel does not take a value corresponding to white and varies along
the first direction x column by column.
In the example described above, since the sub pixels of R and G
respectively concerning V1 and V4 in the column H1 are partially
covered by a part of the light blocking member 313 extending along
the first direction x, for the collection of the sub pixels of
1.times.4, R and G are low in brightness while B and W are
relatively high in brightness as compared with R and G. Similarly,
since the sub pixels of G and B respectively concerning V1 and V4
in the column H2 are partially covered, for the collection of the
sub pixels of 1.times.4, G and B are low in brightness while W and
R are relatively high in brightness as compared with G and B. Since
the sub pixels of B and W respectively concerning V1 and V4 in the
column H3 are partially covered, for the collection of the sub
pixels of 1.times.4, B and W are low in brightness while R and G
are relatively high in brightness as compared with B and W. Since
the sub pixels of W and R respectively concerning V1 and V4 in the
column H4 are partially covered, for the collection of the sub
pixels of 1.times.4, W and R are low in brightness while G and B
are relatively high in brightness as compared with W and R. Thus,
color balance varies column by column, and thus, in the case where
the light blocking members 313 are provided along both of the first
direction x and the second direction y, unevenness of display
color, that is, color moire may occur. That is, white display on
the display device 310 may be visible for the observer as colored
display.
In the above description, the brightness and chromaticity for each
column along the first direction x in the pixel are considered
while a similar phenomenon occurs to the brightness and
chromaticity for each row along the second direction y, which may
cause color moire. The description will be made with reference to
the portrait form depicted in FIG. 10B. The display panel 311 is
placed with the first direction x set as a vertical direction.
Similarly to the landscape display, the light blocking members 313
extending along the first direction x function as a parallax
barrier. Thus, a light beam separation action works along the
second direction y, though too small for the observer to
stereoscopically perceive the planar image. The brightness and
chromaticity of the collection of the sub pixels of 1.times.4
arrayed in each of the columns V1, V2, V3 and V4 along the second
direction y are perceived by the integrated value of the sub pixels
positioned at H1, H2, H3 and H4. In the case of considering the
collection of the four sub pixels arranged in the column V1 in the
horizontal direction in the drawing, the brightness and
chromaticity of the collection of the sub pixels are perceived by
the integrated value of the sub pixels R, G, B and W respectively
positioned at H1, H2 H3 and H4. Here, since the light blocking
member 313 also has a part extending along the second direction y,
the sub pixels of H1 and H4 positioned at the upper and lower ends
in the drawing for each pixel are partly covered. In the example
described above, since the sub pixels of R and W respectively
concerning H1 and H4 are partially covered, for the collection of
the sub pixels of 1.times.4, R and W are low in brightness while G
and B are high in brightness as compared with R and W. Thus, color
balance varies column by column, and thus, in the case where the
light blocking member 313 is provided along both of the first
direction x and the second direction y, unevenness of display
color, that is, color moire may occur.
As has been described above, regardless of the form of display,
whether it is in a landscape form or a portrait form, provision of
the light blocking members 313 may cause color moire and so on. In
the case where the light blocking members 313 are provided so as to
be compatible with both of the landscape form and the portrait
form, this may cause color moire and so on. In the embodiment
below, in order to solve these problems, a display device having a
light blocking unit that stops forming of light blocking areas at
the time of 2D display is described. Further described is a display
device obtained by adding to the above-described display device a
function of displaying in the landscape form and in the portrait
form and a function of capable of switching the extending direction
of the light blocking area.
(Embodiment 1)
The display device 10 according to the present embodiment will be
described below. The display device 10 according to the present
embodiment is provided with a light blocking unit 13 (see FIG. 14)
for forming a light blocking area 136 in stripes (see the first
light-blocking area 136a in FIG. 16A and the second light blocking
area 136b in FIG. 16B) that partially blocks the light emitted from
the display panel 11, and dynamically switches the extending
direction of the light blocking area 136 between the first
direction x and the second direction y depending on the switching
of the display orientation of an image. This switching prevents
color moire from occurring.
FIG. 11A and FIG. 11B is a perspective view of an electronic
apparatus 1 with the display device 10. FIG. 11A depicts a state
where the electronic apparatus 1 is placed in the horizontal
posture while FIG. 11B depicts a state where the electronic
apparatus 1 is placed in the vertical posture. The electronic
apparatus 1 is an electronic apparatus such as a smartphone
similarly to the electronic apparatus 301 according to the related
art. The display device 10 is a display device such as a liquid
crystal display mounted on the electronic apparatus 1 and performs
3D display and 2D display. Furthermore, the display device 10
switches between landscape display and portrait display as
respectively illustrated in FIG. 11A and FIG. 11B depending on the
placed state of the electronic apparatus 1. That is, the display
device 10 performs landscape display in a state placed in a
horizontal posture depicted in FIG. 11A and performs portrait
display in a state placed in the vertical posture depicted in FIG.
11B.
FIG. 12 is a block diagram illustrating an example of the
configuration of the display device 10. The display device 10 is a
3D display device mounted on the electronic apparatus 1 and is, for
example, a liquid crystal display device. The display device 10
includes a control unit 21, a storage unit 22, an image signal
source 23, a posture detection unit 24, a distribution drive
circuit 25, a light blocking drive circuit 26, a reception unit 27,
a display panel 11, a distribution unit 12, and light blocking unit
13.
The control unit 21 includes an arithmetic processor such as a
central processing unit (CPU) and a micro-processing unit (MPU) and
is a display controller for controlling image display processing
concerning the display device 10. The storage unit 22 includes
memory elements such as random access memory (RAM) and read only
memory (ROM) and stores a program or data required for executing
processing by the control unit 21. The storage unit 22 temporarily
stores data or the like required for executing processing by the
control unit 21. The image signal source 23 includes an image
processing circuit (not illustrated) and generates an image signal
for causing the control unit 21 to display an image on the display
panel 11 and applies it to the control unit 21. The image signal
source 23 is connected to a communication antenna (not illustrated)
contained in the electronic apparatus 1, for example, and processes
an image signal input from the outside and applies the resultant to
the control unit 21.
The distribution drive circuit 25 is a drive circuit for driving
the distribution unit 12 in response to the instruction from the
control unit 21. In the case where the distribution unit 12 is a
liquid crystal lens, the distribution drive circuit 25 applies
alternate current (AC) voltage to driving electrodes of the liquid
crystal lens to form a lenticular-lens-like refractive index
profile.
The light blocking drive circuit 26 is a drive circuit for driving
the light blocking unit 13 and drives the light blocking unit 13,
which will be described later, according to an instruction from the
control unit 21.
The posture detection unit 24 detects the posture of the display
device 10. The posture detection unit 24 is, for example, a gyro
sensor for detecting the tilt of the display panel 11 and applies a
detected value to the control unit 21.
The reception unit 27 is an input interface such as a touch panel
and a press button for receiving an operation input from the
observer. The reception unit 27 applies the received content of the
operation to the control unit 21.
By reading out a program P and executing it, the control unit 21
functions as follows. A determination unit 214 determines whether
the display device 10 is placed in the horizontal posture or the
vertical posture based on the result of detection of the posture of
the display device 10 by the posture detection unit 24. A display
control unit 211 performs processing of switching the display state
of the display panel 11 between a first display state to display a
parallax image (3D display) and a second display state to display a
planar image (2D display). Furthermore, the display control unit
211 acquires a determination result from the determination unit 214
and displays a planar image or a parallax image on the display
panel 11 in either landscape form or a portrait form according to
the determination result. In the case of 3D display, a distribution
control unit 212 controls the distribution drive circuit 25
according to the determination result by the determination unit 214
and switches the state of the distribution unit 12 between the
first distribution state and the second distribution state. In the
case of 3D display on the display control unit 211, a light
blocking control unit 213 controls the light blocking drive circuit
26 according to the determination result by the determination unit
214 to cause the light blocking unit 13 to form the light blocking
area 136 described below in accordance with the state of the
distribution unit 12. Note that the control unit 21 may have a
circuit configuration.
FIG. 13 is a partial cross-sectional view illustrating an example
of the configuration of the display device 10. Note that FIG. 13
illustrates a cross-sectional view of the display device 10 taken
from line XIII-XIII of FIG. 11A. The display device 10 according to
the present embodiment includes the display panel 11, the
distribution unit 12 and the light blocking unit 13.
The display panel 11 is a liquid crystal panel and includes two
sheets of transparent substrates 112 and 113 facing each other with
clearance, a liquid crystal layer 111 sealed between the facing
surfaces of the transparent substrates 112 and 113, and polarizers
114 and 115 that are respectively laminated on the front side of
the transparent substrate 112 and on the backside of the
transparent substrate 113. By causing liquid crystal molecules in
the liquid crystal layer 111 to align according to a display image
and causing light emitted from a back light source (not
illustrated) placed at the back side to transmit toward the front
side, an image is displayed.
The display panel 11 is, for example, a twisted nematic (TN) liquid
crystal panel, and the axes of transmission of the polarizers 114
and 115 are perpendicular to each other.
The distribution unit 12 is an electrical optics capable of
switching a light beam separation direction and is a liquid crystal
lens, for example. As illustrated in FIG. 13, the distribution unit
12 includes two sheets of transparent substrates 122 and 123 that
face each other and a liquid crystal layer 121 sealed between the
transparent substrates 122 and 123. Driving electrodes (not
illustrated) are arranged on the facing surfaces of the transparent
substrates 122 and 123, and by application of voltage from an
external voltage source to the driving electrodes, the liquid
crystal molecules in the liquid crystal layer 121 are aligned. This
allows the distribution unit 12 to form a lenticular-lens-like
refractive index profile regarding the second direction y or the
first direction x as an extending direction and distributes the
light emitted from the display panel 11 along the first direction x
or the second direction y.
The light blocking unit 13 is disposed between the display panel 11
and the distribution unit 12. The light blocking unit 13 is an
optical element for blocking part of the light emitted from the
display panel 11 in the case of performing 3D display, and is a
liquid crystal barrier, for example. Description will be made below
regarding the light blocking unit 13 as a liquid crystal barrier.
Note that a polarizer 14 is interposed between the distribution
unit 12 and the light blocking unit 13, and axes of transmission of
the polarizer 14 and the polarizer 114 are perpendicular to each
other.
FIG. 14 is a partial cross-sectional view illustrating an example
of the configuration of the light blocking unit 13. FIG. 15 depicts
an example of the arranged configuration of electrodes 134 and 135.
Similarly to FIG. 13, FIG. 14 depicts a cross-sectional view
perpendicular to the second direction y. The light blocking unit 13
includes two sheets of transparent substrates 132 and 133, a liquid
crystal layer 131 and the electrodes 134 and 135. The transparent
substrates 132 and 133 face each other with clearance. The liquid
crystal layer 131 is sealed between the facing surfaces of the
transparent substrates 132 and 133. Furthermore, the electrodes 134
and 135 are respectively arranged on the facing surfaces of the
transparent substrates 132 and 133. Multiple electrodes 134 each
extending along the second direction y throughout the length of the
short side of the display panel 11 are arranged in stripes along
the first direction x. Multiple electrodes 135 each extending along
the first direction x throughout the length of the long side of the
display panel 11 are arranged in stripes along the second direction
y. As illustrated in FIG. 15, the electrodes 134 and 135 are
orthogonal to each other in front view.
By applying voltage to the electrodes 134 and 135, a part of the
liquid crystal molecules in the liquid crystal layer 131 are
aligned to partially block the light incident from the display
panel 11 to the light blocking unit 13. For example, consider a
case where 3D display is performed in the landscape form. In this
case, voltage is applied to the electrodes 134. More specifically,
voltage is selectively applied to a part of the multiple electrodes
134 arrayed along the first direction x. In FIG. 14, for example,
voltage is selectively applied to the electrodes 134 positioned at
the areas indicated by the reference code 136a (light blocking area
136 described later). Note that the electrode 134 and the electrode
135 to which no voltage is applied are regarded as 0 V. In the case
where voltage is applied to the electrode 134, the liquid crystal
molecules in the liquid crystal layer 131 near the electrode 134 to
which voltage is applied are oriented in the vertical direction.
The light incident from the display panel 11 to the liquid crystal
layer 121 through the transparent substrate 132 is emitted toward
the front side through the transparent substrate 132 as it is at
the part where the liquid crystal molecules are oriented forward
without changing the polarized state. In this case, the axes of
transmission of the polarizer 14 positioned in front of the light
blocking unit 13 and the polarizer 114 positioned at the back
thereof are perpendicular to each other, which causes the polarizer
14 to block the light transmitted through the light blocking unit
13. That is, by applying voltage to the electrodes 134, the light
blocking unit 13 forms the first light blocking areas 136a depicted
in FIG. 14 to thereby block part of the light emitted from the
display panel 11. By selectively applying voltage to the multiple
electrodes 134, the multiple first light blocking areas 136a are
formed to be arrayed along the first direction x as illustrated in
FIG. 14. The electrodes 134 extend along the second direction y,
and thus the first light blocking area 136a extends along the
second direction y. Hence, the multiple first light blocking areas
136a are formed in stripes at the light blocking unit 13 as a
whole.
In the case of 3D display in the portrait form, voltage is applied,
not to the electrode 134 on the back side but to the electrode 135
on the front side. Note that the electrode 135 and the electrode
134 to which no voltage is applied are regarded as 0 V. This allows
second light blocking areas 136b extending along the first
direction x to be formed on the liquid crystal layer 131 (see FIG.
16B). Hence, by selecting either the electrode 134 or the electrode
135 to be applied with voltage, the display device 10 allows the
first light blocking areas 136a and the second light blocking areas
136b to be formed. For the sake of convenience, either or both of
the first light blocking area 136a and the second light blocking
area 136b are represented as the light blocking area 136.
FIG. 16A to FIG. 17B simply depict 3D display according to the
present embodiment. FIG. 16A to FIG. 17B conceptually illustrate a
case where the display panel 11 displays four primary colors
regarding sub pixels of 4.times.4 as a pixel unit. In the case of
the landscape form, for example, the display panel 11 alternately
displays each parallax image corresponding to two columns of sub
pixels along the first direction x as illustrated in FIG. 16A and
FIG. 17A. Furthermore, the distribution unit 12 forms a first
separation area 124a with a forming width corresponding to four
columns of sub pixels along the first direction x and distributes
emitted light concerning each parallax image to each viewpoint. In
the case of performing 3D display in the portrait form, the display
panel 11 alternately displays each parallax image at a pitch
corresponding to two columns of sub pixels along the second
direction y as illustrated in FIG. 16B and FIG. 17B. Furthermore,
the distribution unit 12 forms a second separation area 124b with a
forming width corresponding to four columns of sub pixels along the
second direction y.
Meanwhile, the light blocking unit 13 forms multiple light blocking
areas 136 extending along the first direction x or the second
direction y. In the case of the landscape form, for example, the
light blocking unit 13 forms the multiple first light blocking
areas 136a extending along the second direction y each of which is
arrayed at a pitch corresponding to four columns of sub pixels
along the first direction x such that the light emitted from the
display panel 11 is blocked at each boundary portion between the
separation areas 124 as illustrated in FIG. 16A. The light blocking
unit 13 forms the first light blocking areas 136a extending along
the second direction y at the positions facing the boundary
portions between the first separation areas 124a. Thus, the
boundary portions between the separation areas 124 are covered
while the light blocking area 136 extending along the first
direction x is not formed. That is, the sub pixels positioned at
the upper and lower ends for each pixel in the drawing are not
partially covered. Accordingly, in the case of white display, for
example, the integrated value concerning the brightness and
chromaticity of the light emitted from the sub pixels of V1, V2, V3
and V4 arrayed in each of the columns H1 to H4 represents
substantially the same chromaticity, that is, white for each of the
columns H1 to H4. That is, the integral along the second direction
y concerning the brightness and chromaticity of light emitted in a
pixel represents substantially the same chromaticity, i.e., white
for each column arranged along the first direction x. This makes it
possible to effectively prevent color moire from occurring.
In the case of 3D display in the portrait form, the light blocking
unit 13 switches the extending direction of the light blocking area
136 to the first direction x as illustrated in FIG. 16B and FIG.
17B. More specifically, the light blocking unit 13 forms the
multiple second light blocking areas 136b extending along the first
direction x each of which is arrayed at a pitch corresponding to
four columns of sub pixels along the second direction y. Thus, the
extending direction of the light blocking area 136 can also be
switched in accordance with the switching of the display
orientation of an image, which makes it possible to suitably block
the light emitted from display panel 11 and incident to the
boundary potion of the separation area 124.
Meanwhile, in the case of performing 2D display, the display device
10 stops the operation of the distribution unit 12 and the light
blocking unit 13 to thereby display a planar image on the display
panel 11. More specifically, as illustrated in FIG. 18A to FIG.
19B, only switching of the display orientation of an image between
a landscape form and a portrait form is performed on the display
panel 11, and the distribution unit 12 and the light blocking unit
13 does not respectively form the separation area 124 and the light
blocking area 136. This causes the distribution unit 12 and the
light blocking unit 13 to transmit the light emitted from the
display panel 11 toward the front side as it is. Hence, the display
device 10 may stop distributing the emitted light by the
distribution unit 12 and stop forming the light blocking area 136,
in the 2D display (second display state), whereby the problems of
color moire, 3D moire and so on as illustrated in FIG. 5 may be
avoided.
As described above, the display device 10 switches the extending
direction of the separation area 124 and the light blocking area
136 in accordance with the switching of the display orientation of
an image at the time of 3D display as well as stops forming the
separation area 124 and the light blocking area 136 at the time of
2D display. This makes it possible to prevent color moire or the
like from occurring.
Next, other examples of display patterns of the parallax images are
described using FIG. 20A to 21B. FIG. 20A to FIG. 21B illustrate
examples of display patterns of the parallax images different from
those depicted in FIG. 16A to FIG. 17B. In FIGS. 20A and 20B, each
of the parallax images is alternately displayed at a pitch
corresponding to not two columns of sub pixels but one column of a
sub pixel. In this case, the distribution unit 12 forms each
separation area 124 at a forming width corresponding to two columns
of sub pixels. The display device 10 is provided with the light
blocking unit 13 in place of the light blocking member 313, and the
light blocking unit 13 forms each light blocking area 136 at a
pitch corresponding to two columns of sub pixels. The light
blocking area 136 extends in either the second direction y or the
first direction x depending on the placed state of the display
device 10, which makes it possible to suitably block the light
emitted from the display panel 11 only at the boundary portions
between the separation areas 124.
As described above, even if the display patterns of the respective
parallax images of the sub pixels are changed from the display
patterns illustrated in FIG. 16A to 17B, the distribution unit 12
may distribute emitted light concerning each of the parallax images
to each of the viewpoints. Furthermore, the light blocking unit 13
may prevent light scatter at the boundary portions between the
separation areas 124 from occurring and suppress the occurrence of
color moire and so on.
FIG. 22A and FIG. 22B are illustrative views of examples of array
patterns of sub pixels concerning the three primary colors. Though
the display panel 11 displays four primary colors of RGBW in the
description above, the present embodiment is not limited thereto,
but may display three primary colors of RGB, for example. In this
case, sub pixels of RGB are arrayed as illustrated in FIG. 22A, for
example. More specifically, each pixel consists of sub pixels of
2.times.6. Assuming that sub pixels of two columns consisting of
adjacent odd and even columns, i.e., columns H1 and H2 are regarded
as one unit, each pixel is arrayed along the first direction x for
each unit (that is, by the units of every two columns). In examples
in FIG. 22A and FIG. 22B, adjacent sub pixels arranged along the
first direction x and the second direction y are subjected to color
compensation so as to have different primary colors similarly to
the case of the four primary color.
The display panel 11 displays each parallax image at a pitch
corresponding to one column of a sub pixel, for example. The
distribution unit 12 forms each separation area 124 at a forming
width corresponding to two columns of sub pixels. The light
blocking unit 13 forms each light blocking area 136 at an array
pitch corresponding to two columns of sub pixels. Even in the
configuration illustrated in FIGS. 22A and 22B, that is, in the
case of the three primary colors, an arbitrary color may be
displayed in each pixel. As illustrated in FIGS. 16A and 16B, the
boundary portion between the separation areas 124 is covered while
the light blocking area extending along the first direction x in
FIG. 22A and the light blocking area extending along the second
direction y in FIG. 22B are not formed. Thus, similarly to the
above description, in the case of white display, for example, the
integral along the second direction y concerning the brightness and
chromaticity of light emitted in a pixel represents substantially
the same chromaticity, i.e., white for each column arranged along
the first direction x in FIG. 22A. This makes it possible to
prevent color moire from occurring. In the case of white display,
for example, the integral along the first direction x concerning
the brightness and chromaticity of light emitted in a pixel
represents substantially the same chromaticity, i.e., white for
each column arranged along the second direction y in FIG. 22B. This
makes it possible to prevent color moire from occurring.
FIG. 23A and FIG. 23B are illustrative views of other examples of
array patterns of sub pixels concerning the three primary colors.
Variety of array patterns of pixels may be employed as array
patterns of pixels, not limited to the array patterns in the
above-described embodiments. FIGS. 23A and 23B illustrate array
patterns of sub pixels on which color compensation is not performed
such that adjacent sub pixels have different primary colors unlike
FIG. 22A and FIG. 22B, for example. More specifically, sub pixels
of the same primary color are configured to be aligned along the
second direction y. In FIG. 23A, one 3D pixel consists of sub
pixels of 2.times.1, for example. That is, V1 (or V2) in the
columns H1 and H2, V1 (V2) in the columns H3 and H4, or V1 (V2) in
the columns H5 and H6 are regarded as one 3D pixel. In FIG. 23B,
one pixel consists of sub pixels of 2.times.3. That is, H1, H2 and
H3 (or H4, H5 and H6) in the V1 and V2 columns are regarded as one
pixel. In the case of FIG. 23A, one 3D pixel may not display an
arbitrary color while multiple 3D pixels together may display an
arbitrary color when subjected to image processing. Furthermore, as
illustrated in FIG. 16A and FIG. 16B, the boundary portion between
the separation areas 124 is covered while the light blocking area
136 extending along the second direction y is not formed in FIG.
23B. Hence, in the case of white display, for example, the integral
along the first direction x concerning the brightness and
chromaticity of light emitted in a pixel represents substantially
the same chromaticity, i.e., white for each column arranged along
the second direction y similarly to the above description. This
makes it possible to prevent color moire and so on from
occurring.
FIG. 24 is a flowchart illustrating an example of a processing
procedure to be executed by the control unit 21. The content of the
image processing to be executed by the control unit 21 will be
described based on FIG. 24.
The control unit 21 receives via the reception unit 27 a setting
input as to whether a first display state to display parallax
images or a second display state to display a planar image is
employed (step S11). That is, the control unit 21 receives a
setting input as to whether 3D display or 2D display is to be
performed. The control unit 21 determines whether or not 3D display
is to be performed based on the setting input received at step S11
(step S12). If it is determined that 3D display is performed (S12:
YES), the control unit 21 acquires a detection result acquired by
detecting the posture of its own apparatus from the posture
detection unit 24 (step S13). More specifically, the control unit
21 acquires a detected value concerning the tilt of the display
panel 11. The control unit 21 determines whether or not the
apparatus is placed in the horizontal posture based on the
detection result acquired at step S13 (step S14).
If it is determined the horizontal posture is possible (S14: YES),
the control unit 21 sets the display state of the display panel 11
to the first display state and alternately displays parallax images
for each viewpoints corresponding to multi viewpoints along the
first direction x (step S15). In other words, the control unit 21
displays parallax images in the landscape form.
The control unit 21 further switches the state of the distribution
unit 12 to a first distribution state for distributing light
emitted from each pixel to multi viewpoints along the first
direction x (step S16). More specifically, the control unit 21
controls the distribution drive circuit 25 to drive the
distribution unit 12 and causes multiple first separation areas
124a extending along the second direction y to be formed in an
array along the first direction x. This causes liquid crystal
molecules in the liquid crystal layer 121 to align to thereby form
a lenticular-lens-like refractive index profile in which multiple
cylindrical lenses extending along the second direction y are
arranged along the first direction x.
The control unit 21 further causes the light blocking unit 13 to
form, along the first direction x, multiple first light blocking
areas 136a extending along the second direction y that block part
of the light emitted from each pixel (step S17). More specifically,
the control unit 21 controls the light blocking drive circuit 26 to
selectively apply voltage to a part of the electrodes 134
positioned at the boundary portions between the respective
separation areas 124 of the distribution unit 12 out of the
multiple electrodes 134 arranged in stripes. Thus, a part of the
liquid crystal molecules in the liquid crystal layer 131 align so
as to be arrayed at a pitch substantially the same as the forming
width of each separation area 124 of the distribution unit 12,
which forms multiple first light blocking areas 136 covering the
boundary portions between the respective separation areas 124. The
control unit 21 shifts the processing to step S24.
If it is determined the horizontal postured is not possible (S14:
NO), the control unit 21 sets the display state of the display
panel 11 to the first display state and alternately displays each
of the parallax images along the second direction y (step S18). In
other words, the control unit 21 displays a parallax image in the
portrait form. The control unit 21 switches the distribution unit
12 to a second distribution state for distributing emitted light to
multi viewpoints along the second direction y (step S19). More
specifically, the control unit 21 causes the distribution unit 12
to form multiple second separation areas 124b extending along the
first direction x. The control unit 21 causes the light blocking
unit 13 to form, along the second direction y, multiple second
light blocking areas 136b extending along the first direction x
that block part of the light emitted from each pixel (step S20).
The control unit 21 shifts the processing to the step S24.
If it is determined that 3D display is not performed (S12: NO), the
control unit 21 sets the display state of the display panel 11 to
the second display state to thereby display a planar image for 2D
display on the display panel 11 (step S21). The control unit 21
stops forming the separation areas 124 by the distribution unit 12
(step S22). The control unit 21 stops forming the light blocking
areas 136 by the light blocking unit 13 (step S23).
After execution of the processing in the step S17, S20 or S23, the
control unit 21 determines whether or not image display processing
is to be ended (step S24). For example, the control unit 21
determines whether or not an operation input concerning an end
instruction is received via the reception unit 27. If it is
determined that the processing is not to be ended (S24: NO), the
control unit 21 returns the processing to step S11. If it is
determined that the processing is to be ended (S24: YES), the
control unit 21 ends a series of processing.
It is noted that description is made taking the case where the
first direction x and the second direction y are perpendicular to
each other as an example in the above description, though the
embodiment is not restricted thereto. FIG. 25 illustrates another
example of the configuration of the display device 10. As depicted
in FIG. 25 for example, the display panel 11 may be configured to
be rhombic, not rectangular. Even in this case, by changing the
shape of the separation areas 124 and the light blocking areas 136
in accordance with the arrangement configuration of the respective
pixels, 3D display is made possible. That is, the display device 10
according to the present embodiment is applicable even if the first
direction x and the second direction y are not perpendicular to
each other.
Note that the display device 10 according to Embodiment 1 has a
function of being capable of switching between the landscape
display and the portrait display as well as a function of being
capable of switching the extending direction of the light blocking
area 136, but these two functions need not to be provided. If the
two functions are not provided, the posture detection unit 24 and
the determination unit 214 are not required, and the display
control unit 211 does not execute processing for displaying a
planar image or a parallax image on the display panel 11 in either
the landscape form or the portrait form. Furthermore, the light
blocking unit 13 does not execute switching of the extending
direction of the light blocking areas 136.
In addition, the display device 10 according to Embodiment 1 has a
function of being capable of displaying in the landscape form and
the portrait form as well as a function of being capable of
switching the extending direction of the light blocking area 136
while it may not have a function of stopping distribution of the
emitted light by the distribution unit 12 at the time of 2D display
(second display state).
Hence, according to the Embodiment 1, the display device 10
performs distribution of emitted light and formation of the light
blocking areas 136 by driving the distribution unit 12 and the
light blocking unit 13 respectively at the time of 3D display
(first display state) while stopping performing distribution of
emitted light and formation of the light blocking areas 136 without
driving the distribution unit 12 and the light blocking unit 13 at
the time of the 2D display (second display state). This makes it
possible to avoid the problems such as color moire, 3D moire and so
on described above and acquire better display characteristics.
Moreover, according to Embodiment 1, even if the display device 10
is configured to be switchable between the landscape display and
the portrait display, the extending direction of the light blocking
areas 136 is switched depending on the display orientation of an
image, which enables 3D display appropriately while reducing
occurrence of color moire and so on.
In addition, according to Embodiment 1, the light blocking areas
136 are formed at each boundary portion between the respective
separation areas 124, which may appropriately prevent the color
moire and so on from occurring.
Furthermore, according to Embodiment 1, multiple sub pixels aligned
along the first direction x or the second direction y along which
the light blocking areas 136 extend are equal in number for each of
the different colors within a pixel. Accordingly, in the case of
white display, for example, the integrated value in the extending
direction of the light blocking area 136 concerning the brightness
and chromaticity of light emitted in a pixel is substantially the
same chromaticity, i.e., white for each column arranged in the
direction perpendicular to the light blocking area 136. By setting
colors of each of the sub pixels as described above, occurrence of
color moire may be effectively suppressed.
In addition, according to Embodiment 1, unlike FIGS. 23A and 23B,
the colors of the adjacent sub pixels are subjected to color
compensation so as to have different colors as in FIG. 16A, FIG.
16B, FIG. 20A, FIG. 20B, FIG. 22A and FIG. 22B. By this color
compensation, occurrence of color moire may be effectively
suppressed on both display in the portrait form and the landscape
form.
(Embodiment 2)
Description is made taking two viewpoints as an example in
Embodiment 1, but light blocking control in Embodiment 1 may be
applied to viewpoints more than two viewpoints, not limited to two
viewpoints. In the present embodiment, description is made on the
case where the display device 10 performs image display directed to
viewpoints more than two viewpoints. It is noted that the contents
overlapped with those in Embodiment 1 will not be described by
applying the same reference codes to the drawings.
Before describing the present embodiment, a related art concerning
image display directed to multi viewpoints and its problem will be
described. FIG. 26A and FIG. 26B depict image display directed to
multi viewpoints. FIG. 26A and FIG. 26B respectively illustrate the
case where image display directed to two viewpoints is performed
similarly to Embodiment 1 and the case where image display directed
to eight viewpoints is performed unlike Embodiment 1.
In the case of image display directed to two viewpoints illustrated
in FIG. 26A, 3D display is performed regarding two sub pixels as
one pixel, and a left eye image and a right eye image are
alternately displayed in each of the sub pixels along the first
direction x. Furthermore, in FIG. 26A, separation areas 3124 each
having a forming width corresponding to two columns of sub pixels
are formed in accordance with the display patterns of the parallax
images on the display panel 311.
Meanwhile, in the case of image display directed to eight
viewpoints illustrated in FIG. 26B, 3D display is performed
regarding eight sub pixels as one pixel, and each of the images
directed to the eight viewpoints are displayed in each of the sub
pixels along the first direction x. That is, the display panel 311
displays an image for first viewpoint, an image for second
viewpoint, an image for third viewpoint, an image for fourth
viewpoint . . . on each of the sub pixels one after another. The
display device 310 further forms on the liquid crystal lens a
separation area 3124 having a width corresponding to eight columns
of sub pixels along the first direction x in accordance with the
display on the display panel 311. Thus, the image for each of the
respective viewpoints is distributed to eight viewpoints as
illustrated in FIG. 26B.
The display device 310 thus displays images depending the number of
viewpoints on the display panel 311 and changes the forming width
of the separation area 3124 according to the number of viewpoints.
This makes it possible to perform 3D display directed to two
viewpoints as well as multi viewpoints.
However, if the light blocking members 313 are provided in
accordance with any one of the number of viewpoints, change in the
number of viewpoints may lead to reduction in efficiency of
utilization of emitted light and scattering of the emitted light.
FIGS. 27A to 27F depict a problem for a related art. FIGS. 27A to
27C depict a case where light blocking members 313 placed at a
pitch corresponding to two columns of sub pixels are provided in
accordance with two viewpoints. FIGS. 27D to 27F depict a case
where light blocking members 313 placed at a pitch corresponding to
eight columns of sub pixels are provided in accordance with eight
viewpoints. FIGS. 27A and 27D depict a case where image display
directed to two viewpoints is performed, FIGS. 27B and 27E depict a
case where image display directed to four viewpoints is performed,
and FIGS. 27C and 27F depict a case where image display directed to
eight viewpoints is performed.
As illustrated in FIG. 27A to FIG. 27C, in the case where the light
blocking members 313 are provided at a pitch corresponding to two
columns of sub pixels in accordance with two viewpoints, the
boundaries between the separation areas 3124 are suitably blocked
in FIG. 27A while the light emitted incident to the portions
different from the boundaries between the separation area 3124 is
also blocked in FIG. 27B and FIG. 27C. This causes reduction in
efficiency of utilization of the light emitted from the display
panel 311.
As illustrated in FIGS. 27D to 27F, in the case where the light
blocking members 313 are provided at a pitch corresponding to eight
columns of sub pixels in accordance with eight viewpoints, the
boundaries between the separation areas 3124 are suitably blocked
in FIG. 27F while the boundaries between the separation areas 3124
that are not blocked by the light blocking areas 313 exist in FIG.
27D and FIG. 27E. This may cause scatter of light emitted from the
display panel 311 and degradation in display characteristics.
Hereupon, in the present embodiment, by utilizing the light
blocking unit 13 in place of the light blocking member 313 and by
dynamically controlling the array pitch of the light blocking area
136 depending on the number of viewpoints, the above-described
problems are solved.
FIG. 28A to FIG. 29B simply depict image display directed to four
viewpoints. In FIG. 28A to FIG. 29B, each pixel consists of sub
pixels of 4.times.4. In the configuration in FIG. 28A to FIG. 29B,
the display panel 11 displays an image for each viewpoint at a
pitch corresponding to one column of a sub pixel. In the case of
the landscape form, for example, as illustrated in FIG. 28A and
FIG. 29A, the display panel 11 displays an image for first
viewpoint, an image for second viewpoint, an image for third
viewpoint and an image for fourth viewpoint one after another along
the first direction x. For example, the image for the first
viewpoint is displayed in the column H1, the image for second
viewpoint is displayed in the column H2, the image for third
viewpoint is displayed in the column H3, and the image for the
fourth viewpoint is displayed in the column H4.
The distribution unit 12 and the light blocking unit 13
respectively form the separation areas 124 and the light blocking
areas 136 depending on the number of viewpoints. In the case of
displaying in a landscape form, for example, the distribution unit
12 forms multiple separation areas 124 extending along the second
direction y each having a width corresponding to four columns of
sub pixels as illustrated in FIG. 28A. Furthermore, the light
blocking unit 13 forms multiple light blocking areas 136 extending
along the second direction y placed at an array pitch corresponding
to four columns of sub pixels at the boundary portions between the
separation areas 124. By the above configuration, the light emitted
from each of the parallax images displayed on each pixel is
distributed to four viewpoints. This makes it possible to display
separate images for multi viewpoints. Example is that two observers
can recognize separate stereoscopic images, for example.
In addition, similarly to Embodiment 1, the display device 10
performs switching of the display orientation according to the
posture of its own apparatus. That is, if the apparatus switches
from the horizontal posture to the vertical posture, the display
form of the display panel 11 is switched from the landscape form to
the portrait form to thereby cause the display panel 11 to
alternately display parallax images along the second direction y as
illustrated in FIG. 28B and FIG. 29B. In this case, the
distribution unit 12 and the light blocking unit 13 respectively
switch the extending directions of the separation areas 124 and the
light blocking areas 136 from the second direction y to the first
direction x.
FIG. 30A to FIG. 32B are illustrative views when image display
directed to multi viewpoints is made. FIG. 30A and FIG. 30B
illustrate an example of configuration when image display directed
to six viewpoints is performed, FIG. 31A and FIG. 31B illustrate an
example of configuration when image display directed to eight
viewpoints is performed, and FIG. 32A and FIG. 32B illustrate an
example of configuration when image display directed to twelve
viewpoints is performed. In FIG. 30A and FIG. 30B, each pixel
consists of sub pixels of 6.times.4. In FIG. 31A and FIG. 31B, each
pixel consists of sub pixels of 8.times.8. Note that sub pixels of
8.times.4, for example, may be regarded as a pixel unit in FIG. 31A
and FIG. 31B. In FIG. 32A and FIG. 32B, each pixel consists of sub
pixels of 12.times.12. Note that sub pixels of 12.times.4 may be
regarded as a pixel unit in FIG. 32A and FIG. 32B.
Even in the configuration illustrated in FIG. 30A to FIG. 32B, the
display panel 11 display an image for each viewpoint at a pitch
corresponding to one column of sub pixel. Furthermore, the
distribution unit 12 adjusts the forming width of each separation
area 124 depending on the number of viewpoints. In the case of six
viewpoint display, for example, the distribution unit 12 forms each
separation area 124 having a forming width of six columns of sub
pixels. The same applies to eight viewpoint display and twelve
viewpoint display. Meanwhile, the light blocking unit 13 adjusts
the array pitch of each light blocking area 136 depending on the
number of viewpoints. In the case of six viewpoint display, for
example, the light blocking unit 13 forms the light blocking areas
136 placed at an array pitch corresponding to six columns of sub
pixels.
The display device 10 respectively drives the distribution unit 12
and the light blocking unit 13 according to the change in the
number of viewpoints to thereby change the forming width of the
separation area 124 and the forming position of the light blocking
area 136 as described above. FIG. 33 is a flowchart depicting an
example of a processing procedure to be executed by the control
unit 21. The processing to be performed by the display device 10
will be described with reference to FIG. 33.
If it is determined that 3D display is performed (S12: YES), the
control unit 21 of the display device 10 receives a setting input
about the number of viewpoints via the reception unit 27, for
example (step S201). The control unit 21 shifts the processing to
step S13.
If it is determined that the horizontal posture is possible (S14:
YES), the control unit 21 alternately displays a parallax image for
each viewpoint along the first direction x depending on the number
of viewpoints set at step S201 (step S202). That is, the control
unit 21 displays an image for each viewpoint along the first
direction x one after another as illustrated in FIG. 28A, etc. The
control unit 21 switches the state of the distribution unit 12 to a
first distribution state to cause the distribution unit 12 to form
each first separation area 124a having a width depending on the
number of viewpoints along the first direction x (step S203). Thus,
the control unit 21 changes the width of each first separation area
124a along the first direction x depending on the number of
viewpoints. The control unit 21 drives the light blocking unit 13
to form the first blocking area 136a at each boundary between the
first separation areas 124a in correspondence to the changed width
of the first separation area 124a (step S204).
If it is determined the horizontal posture is not possible (S14:
NO), the control unit 21 alternately displays a parallax image for
each viewpoint along the second direction y depending on the number
of viewpoints set at step S201 (step S205). The control unit 21
switches the state of the distribution unit 12 to the second
distribution state to cause the distribution unit 12 to form each
second separation area 124b having a width depending on the number
of viewpoints along the second direction y (step S206). That is,
the control unit 21 changes the width of each second separation
area 124b along the second direction y depending on the number of
viewpoints. The control unit 21 drives the light blocking unit 13
to form the second blocking area 136b at each boundary between the
second separation areas 124b in correspondence to the changed width
of the second separation area 124b (step S207).
It is noted that description is made on display in the four primary
colors, but it is needless to say that image display in the three
primary colors may be possible as described using FIG. 22A to FIG.
23B or the like in Embodiment 1.
Hence, the boundary portions between the separation areas 124 are
covered as illustrated in FIG. 16A and FIG. 16B while no light
blocking areas extending along the first direction x are formed as
illustrated in FIG. 28A, FIG. 29A to FIG. 32A in Embodiment 2 and
no light blocking areas extending along the second direction y are
formed as illustrated in FIG. 28B, FIG. 29B to FIG. 32B in
Embodiment 2. Thus, similarly to the above description, occurrence
of color moire and so on may be prevented even if the display
device 10 performs image display directed to multi viewpoints more
than two viewpoints.
(Embodiment 3)
In the present embodiment, description is made on the case where 3D
display is performed depending on the position of the observer.
FIG. 34 is a block diagram illustrating an example of the
configuration of the display device 10. The display device 10
according to the present embodiment is provided with a position
detection unit 28. The position detection unit 28 includes a camera
or the like for imaging the space in front of the electronic
apparatus 1, for example, recognizes the positions of the eyes of
the observer by image recognition processing, and applies the
recognition result to the control unit 21.
FIG. 35A and FIG. 35B depicts the outline of 3D display processing
according to Embodiment 3. In a method of 3D display with naked
eyes, the optimum position for the observer to observe parallax
images is generally previously set. As illustrated in FIG. 35A, for
example, the optimum observation position is set to the position in
front of the display panel 11 at the center. As illustrated in FIG.
35B, if the position of the viewpoint of the observer is sifted
from the optimum position, a problem in which light emitted not
from a right eye image but from a left eye image may enter the
right eye of the observer occurs. Thus, parallax images may not
appropriately be perceived. According to the present embodiment, by
controlling the separation direction of each parallax image
depending on the position of the observer, the parallax image can
appropriately be perceived even if the viewpoint of the observer is
shifted from the optimum position.
According to the present embodiment, description will be made on a
display device that performs light beam separation by the light
blocking unit 13 without using the distribution unit 12 in order to
reduce the switching time of the light beam separation direction,
for example. That is, the display device 10 causes the light
blocking unit 13 to function as an active parallax barrier.
FIG. 36A and FIG. 36B simply depict 3D display according to
Embodiment 3. FIG. 36A depicts a landscape form while FIG. 36B
depicts a portrait form. Note that FIG. 36A and FIG. 36B illustrate
a case where two viewpoint display is performed regarding sub
pixels of 4.times.4 as a pixel unit.
In the present embodiment, the distribution unit 12 is switched to
a third state where distribution of light emitted from each pixel
is not performed. That is, the distribution unit 12 is set to a
stopped state without being driven. Accordingly, the distribution
unit 12 causes light incident from the back side to directly
transmit toward the front side without forming the separation areas
124.
The light blocking unit 13 forms a light blocking area 136 wider
than the light blocking area 136 according to Embodiment 1 and
covers a part of each pixel in front view. More specifically, the
light blocking unit 13 changes the forming width along the first
direction x or the second direction y different from the extending
direction of the light blocking area 136. In the case of a
landscape form illustrated in FIG. 36A, for example, the light
blocking unit 13 forms the first light blocking area 136a with a
forming width corresponding to two columns of sub pixels along the
first direction x. That is, the light blocking unit 13 forms the
first light blocking area 136a with about half the width of a
pixel. This makes each pixel half covered and half exposed along
the first direction x. In other words, a slit is formed between the
blocking areas 136. In the case of 3D display in the portrait form,
the light blocking unit 13 changes the forming width of the sub
pixels along the second direction y to the width corresponding to
two columns of sub pixels to thereby form the second light blocking
area 136b.
FIG. 37A and FIG. 37B illustrate states where the forming position
of the light blocking areas 136 are switched depending on the
positions of the viewpoints of the observers. Note that FIGS. 37A
and 37B illustrate only the case of display in a landscape form. As
described above, the light blocking unit 13 changes the forming
width of each light blocking area 136 to thereby form a slit
between the light blocking areas 136. Thus, as illustrated in FIG.
37A, light from each of the sub pixels displaying the right eye
image and left eye image is distributed to two directions through a
slit between the light blocking areas. Thus, the display device 10
causes the light blocking unit 13 to function as an active parallax
barrier to perform light beam separation.
In addition, the light blocking unit 13 changes the forming
position of the light blocking area 136 depending on the position
of each observer. More specifically, as illustrated in FIG. 37A and
FIG. 37B, the light blocking unit 13 changes the forming position
of the light blocking area 136 relative to each pixel. In both of
the configurations illustrated in FIG. 37A and FIG. 37B, the
forming width of the light blocking area 136 along the first
direction x is about one half of a pixel. However, the forming
positions of the light blocking areas 136 are different between
FIG. 37A and FIG. 37B. More specifically, the light blocking area
136 in FIG. 37B is changed to a position toward the right in the
drawing as compared with that in FIG. 37A. Thus, the separation
direction of the emitted light concerning each parallax image is
changed toward the right as illustrated in FIG. 37B as compared
with FIG. 37A. The control unit 21 changes the forming position of
the light blocking area 136 as depicted in FIG. 37B if it is
determined that the position of the viewpoint of the observer are
positioned toward the right. Thus, the control unit 21 controls the
light beam separation direction of each of the parallax images by
the light blocking unit 13 depending on the position of the
observer.
FIG. 38A and FIG. 38B depict four viewpoint display according to
Embodiment 3. Note that FIG. 38A and FIG. 38B illustrate the case
of a landscape form. FIG. 38A illustrates the case where each
observer is in a position in front of the display panel 11 at the
center while FIG. 38B illustrates the case where each observer is
in a position toward the right in the drawing as compared with that
in FIG. 38A. In the case of four viewpoint display in a landscape
form, the display panel 11 alternately displays four patterns of
parallax images along the first direction x similarly to Embodiment
1. In this case, the light blocking unit 13 changes the forming
width and forming position of the light blocking area 136 depending
on the position of the observer as described above. For example, as
depicted in FIGS. 38A and 38B, the light blocking unit 13 forms the
light blocking area 136 with half the width of an array pitch of
each pixel. Note that in FIG. 37A to 38B, the forming width of the
light blocking area 136 is the same in both of the cases of two
viewpoints and four viewpoints but may be different depending on
the number of viewpoints. Additionally, as depicted in FIG. 38A and
FIG. 38B, the light blocking unit 13 changes the forming position
of the light blocking area 136 depending on the position of the
observer. Thus, even in the multi viewpoints, the display device 10
enables 3D display depending on the position of the observer.
FIG. 39 is a flowchart depicting an example of a processing
procedure to be executed by the control unit 21 according to
Embodiment 3. After executing processing for detecting the posture
of its own apparatus by the posture detection unit 24 (step S13),
the control unit 21 of the display device 10 executes the following
processing. The control unit 21 determines whether or not 3D
display is performed depending on the position of the observer
(step S301). For example, the control unit 21 receives a setting
input about whether dynamic display control is to be performed at
the time of receiving the operation concerning step S11. The
control unit 21 performs determination according to the content of
the setting. If it is determined that 3D display depending on the
position of the observer is not performed (S301: NO), the control
unit 21 shifts the processing to step S14.
If it is determined that 3D display depending on the position of
the observer is performed (S301: YES), the control unit 21 acquires
the detection result acquired by detecting the position of the
observer from the position detection unit 28 (step S302). For
example, the control unit 21 acquires the processing result of
image recognition processing by the position detection unit 28. The
control unit 21 determines whether or not the apparatus is placed
in the horizontal posture (step S303). If it is determined the
horizontal posture is possible (S303: YES), the control unit 21
sets the display state of the display panel 11 to the first display
state and alternately displays parallax images along the first
direction x (step S304).
The control unit 21 stops driving control on the distribution unit
12 to stop distributing light emitted from each pixel (step S305).
That is, the control unit 21 does not drive the distribution unit
12 so as not to form the separation area 124. Thus, the light
emitted from the display panel 11 is not separated by the
distribution unit 12.
The control unit 21 stops distributing the emitted light by the
distribution unit 12 and then causes the light blocking unit 13 to
form the first light blocking area 136a by changing the forming
width and the forming position along the first direction x
depending on the position of the observer detected by the position
detection unit 28 (step S306). More specifically, the control unit
21 selects the electrode 134 to be applied with voltage depending
on the position of the observer and controls the forming width of
the first light blocking area 136a along the first direction x.
Furthermore, the control unit 21 controls the forming position of
the light blocking area 136 relative to each pixel depending on the
position of the observer. Thus, the control unit 21 causes the
light blocking unit 13 to function as an active parallax barrier to
thereby dynamically control the light beam separation direction
concerning parallax images. The control unit 21 shifts the
processing to step S24.
If it is determined that the horizontal posture is not possible
(S303: NO), the control unit 21 sets the display state of the
display panel 11 to the first display state to thereby alternately
display parallax images along the second direction y (step S307).
The control unit 21 stops distributing the emitted light by the
distribution unit 12 (step S308). The control unit 21 stops
distributing the emitted light and then causes the light blocking
unit 13 to form the second light blocking area 136b by changing the
forming width and the forming position of the second light blocking
area 136b along the second direction y depending on the position of
the observer detected by the position detection unit 28 (step
S309). The control unit 21 shifts the processing to step S24.
Hence, according to Embodiment 3, the separation direction of the
emitted light concerning each parallax image can be controlled
depending on the position of the observer, which increases the
flexibility as to the position of the viewpoint of the
observer.
It is to be noted that, as used herein and in the appended claims,
the singular forms "a," "an," and "the" include plural referents
unless the context clearly dictates otherwise.
It is to be noted that the disclosed embodiment is illustrative and
not restrictive in all aspects. The scope of the present invention
is defined by the appended claims rather than by the description
preceding them, and all changes that fall within metes and bounds
of the claims, or equivalence of such metes and bounds thereof are
therefore intended to be embraced by the claims.
* * * * *